The embodiments described herein relate generally to methods and systems for operating a wind turbine having an active flow control system and, more particularly, to methods and systems for operating an air distribution system during periods of electrical power loss.
Active Flow Control (AFC) is a general term for technologies and/or systems that actively attempt to influence an aerodynamic response of an object in reaction to given in-flow conditions. More specifically, at least some known AFC systems are used to manipulate flow conditions across a blade. As used herein, the term “airfoil” refers to a turbine blade, a wing, and/or any other suitably airfoil. In contrast to known passive flow control systems that provide substantially constant flow control, known AFC systems enable flow control to be selectively applied to an airfoil. At least some known AFC systems use air distribution systems to manipulate a boundary layer of air flowing across a surface of an airfoil.
At least some known AFC systems require power to operate a flow control device to drive air through the air distribution systems. During an event of power loss, AFC systems may not be able to operate. The power loss event may include power grid loss, malfunctioning of the turbine electrical system, and/or failure of the AFC air distribution system. Failure of the AFC air distribution system includes failure of the AFC flow control device electrical system, control system, and/or mechanical system. The power loss event may lead to turbine blade overspeed, during which the AFC system may not be available. Known AFC systems include a fail-safe or safe-life AFC air distribution system to compensate for periods of electrical power loss.
Accordingly, it is desirable to provide a method and/or apparatus capable of operating the AFC system during periods of electrical power loss.